Re: Regression with stdin handling in non-interactive mode between 5.8 and 5.8.1

[Peter Stephenson <p.w.stephenson@ntlworld.com>]

> On 03 March 2022 at 09:39 Peter Stephenson <p.w.stephenson@ntlworld.com> wrote> > On 02 March 2022 at 22:38 Lyude Paul <lyude@redhat.com> wrote:
> > Running on zsh 5.8 returns:
> > 
> >    Shell is 70
> >    Shell is 71
> > 
> > Running on zsh 5.8.1 however, returns:
> > 
> >    Shell is 86396
> >    Shell is 86396
> 
> Thanks for the nice simple test --- I'll try and concoct something similar
> but predictable for the shell tests.

Added to the patch; I've confirmed this succeeds or fails as expected.

pws

diff --git a/Src/input.c b/Src/input.c
index caeaff0e3..50cd2cd78 100644
--- a/Src/input.c
+++ b/Src/input.c
@@ -223,13 +223,20 @@ shingetchar(void)
 	return STOUC(*shinbufptr++);
 
     shinbufreset();
-    do {
+    for (;;) {
 	errno = 0;
-	nread = read(SHIN, shinbuffer, SHINBUFSIZE);
-    } while (nread < 0 && errno == EINTR);
-    if (nread <= 0)
+	nread = read(SHIN, shinbufendptr, 1);
+	if (nread > 0) {
+	    /* Use line buffering (POSIX requirement) */
+	    if (*shinbufendptr++ == '\n')
+		break;
+	    if (shinbufendptr == shinbuffer + SHINBUFSIZE)
+		break;
+	} else if (nread == 0 || errno != EINTR)
+	    break;
+    }
+    if (shinbufendptr == shinbuffer)
 	return -1;
-    shinbufendptr = shinbuffer + nread;
     return STOUC(*shinbufptr++);
 }
 
diff --git a/Test/A01grammar.ztst b/Test/A01grammar.ztst
index 4e39a8f3c..0312fe94e 100644
--- a/Test/A01grammar.ztst
+++ b/Test/A01grammar.ztst
@@ -961,3 +961,12 @@ F:Note that the behaviour of 'exit' inside try-list inside a function is unspeci
 F:This test was written to ensure the behaviour doesn't change silently.
 F:If this test fails during development, it *might* be appropriate to change
 F:its expectations.
+
+ (
+   export VALUE=first
+   print -l 'echo Value is $VALUE' 'VALUE=second sh' 'echo Value is $VALUE' |
+   $ZTST_testdir/../Src/zsh -f
+ )
+0:Non-interactive shell command input is line buffered
+>Value is first
+>Value is second